Dampened railway truck



May 13, 1969 Filed June 12 1967 J- M. .LIPSIUS ET AL DAMPENED RAILWAYTRUCK Sheet v of 7 III INVENTORS g JOHANNES MARTIN LIPSIUS P L EUGENSEHR ATTORNEY May 13, 1969 J;M.:L| Ps|us 'ETAL 3,443,52

DAMPENED RAILWAY 'TRUCK Filed June 12, 1967 Sheet 2 of 7 FIG. 30 a 2 a IFIG. 3d

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ATT EY y 13, 1 J. M. |..|P s| us ET AL- DAMPENED RAILWAY TRUCK FiledJune 12, 1967 FIGB FIG]

May 13, 1969 Ps u ET AL 3,443,528

DAMPEN ED RAILWAY TRUCK Filed June 12'. 1967 Sheet 4 of 7 1:2" L; z |n rL FIG.|4 6 5 I 5 May 13, 1969 1 J. M. LIPSIU S E AL 3,443,528

7 I DAMPENED RAILWAY TRUCK Filed June 12, 1967 -5 FIGIZ 2 Sheet 5 of '7May 13, 19 69 J. LIPSIUS ET AL 3,443,528

DAMPENED RXiLwAY TRUCK Filed June 12. 1967 Sheet 6 of? all!!! v Fl(3.l9H020 v F7 33 r| 2 km 3| J ISO 3 i j I 39 May 13, 1969 Sheet Filed June12, 1967 FIG. 23

United States Patent 3,443,528 DAMPENED RAILWAY TRUCK Johannes MartinLipsius, Kassel, and Eugen Spehr, Kassel- Harleshausen, Germany,assiguors to Rheinstahl Henschel A.G., Kassel, Germany, a corporation ofGermany Continuation-impart of application Ser. No. 470,464, July 8,1965. This application June 12, 1967, Ser. No. 657,450 Claims priority,application Germany, Feb. 26, 1965,

Int. (:1. B611? /10, 5/20, 5/12 U.S. Cl. 105171 11 Claims ABSTRACT OFTHE DISCLOSURE This application is a continuation-in-part of ourcopending application Ser. No. 470,464, filed July 8, 1965, nowabandoned.

Railway vehicles, particularly those having trucks, are frequentlyequipped with transverse spring systems in order to elastically absorblateral shocks and the transverse movements caused by the sinusoidalpath or course of the axles so that the starting forces between thewheels and the rails are reduced. A vehicle which is equipped with atransverse spring suspension system is a system capable of vibrating inthe transverse direction. The frequency of the vibration excited by thesinusoidal path increases with increasing traveling speed so thatresonance with the natural oscillation frequency of the vehicle springsystem may occur at certain speeds.

In order to maintain the transverse vibration or oscillation amplitudesas small as possible over the entire traveling speed range, it isadvisable to select the natural transverse frequency to be as low aspossible, for example, 1 cycle per second. The resonance will then occurat a relatively low traveling speed, whereas at higher traveling speeds,i.e., in the overcritical range, the excited oscillation amplitudes aresmaller than the excitation amplitudes, insofar as the higher excitingfrequency caused by the greater traveling speed amounts to more than 1.4times the natural oscillation frequency. With a further increase in theexcitation frequencies, the amplitudes of the excited oscillationsbecome progressively smaller. However, if a vehicle maintains a speed,over a prolonged period of time, at which there will be resonancebetween the excitation frequency and the natural oscillation frequency,a significant build-up of the oscillation amplitudes will occur. Outsideof the resonance range, these oscillation amplitudes may additionally beminimized by dampers having a constant damping force, for examplefriction dampers, but in the resonance range, this damping elfect ispossible only by means of a damping action which is dependent upon thespeed of the oscillations. With the increasing damping action, theresonance amplitudes of the excited oscillations become smaller and,when the spring action is completely blocked by the damping action, theydiminsh to the magnitude of the excitation amplitudes. This, however,will produce the disadvantage that the wheel flanges run up against therunning or inner 3,443,528 Patented May 13, 1969 edges of the rails intoo hard a manner and, thus, will result in an increased wear and tear,as well as undesirably high shock or impact forces in the entirevehicle.

Above the resonance range, on the other hand, i.e., at a ratio of theexcitation frequency to the natural oscillation frequency of more than1.4:1, the damping action will have an unfavorable effect so that theoscillation amplitudes will be increased until, in the border-line caseof blocking of the spring suspension system, the entity of theexcitation amplitude will equally arise. In order to permit a completeutilization of the favorable properties of an undamped spring suspensionsystem in the overcritical range, the damping action accordingly mustnot be too large unless the damper is provided with a device fordisconnecting it or for reducing the damping effect. In exchangetherefor, oscillation amplitudes must be accepted, in the resonancerange or below, which are considerably greater than the excitationamplitudes.

The construction of the present invention utilizes the advantages of anundamped oscillation in the overcritical range as well as an effectivedamping action in the resonance range and below in a manner such thatoptimum running properties of the vehicle are obtained insofar as thetransverse vibrations or oscillations are concerned. The transverseoscillation amplitudes in the resonance range should become as small aspossible while, however, the smoothness -or elasticity of the transversespring suspension action simultaneously must not be impaired, so thathard impacts are eliminated when the wheel flanges run up or startagainst the running or inner edges of the rails.

In the construction of the present invention, one, or more than one,transverse oscillation damper is mounted outside of the verticaltransverse central plane of the truck, for example at a terminal crossbearer member of the truck frame, in a manner such that during thesinusoidal path or course of the truck, there will be a phase shiftbetween the damper movement and the trans verse spring movement. Thetransverse oscillation damper may be mounted adjacent the end of thevehicle or adjacent the center of the vehicle or at both ends of thetruck with one damper being disconnected, depending upon the directionof travel. For purposes of damping with an oscillation speed-dependentdamping force, hydraulic, pneumatic or electric dampers may be employed,the latter being in the form of an eddy-current brake, for example.

In order to fully utilize the advantages of the overcritical vehiclemovement or course at a higher excitation frequency, the damper shouldbe controllable fin depend ence upon the frequency and should bedisconnected in the border-line case. The frequency-dependent dampingeffect also may be automatically achieved by a series or consecutiveconnection of transverse oscillation dampers and additional springs.

It is known that in railway vehicles equipped with trucks, the truckaxles execute a sinusoidal movement similarly as do those in freelyrolling individual axles, and both truck axles also travel generally intandem on the same sinusoidal wave path. Consequently, the truck framealso executes rotary movements in addition to the transverse movements.Due to the provision of a damper between the truck and the vehicleframe, for example a bridge carrier member, outside of the verticaltransverse central plane of the truck, a phase shift between thetransverse spring movement and the damping movement is effected. Thishas the result that the transverse oscillations of the vehicle body aredamped in the resonance r'ange sufliciently that the amplitudes of theexcited oscillations become smaller than the excitation amplitudes.

Both the rotary movement of the truck and the transverse movementthereof are influenced as a result of the damping action, which isphase-shifted with regard to the spring movement. This produces adirective force which constantly seeks to guide the truck within thecentral position within the rails and, thus, stabilizes the movement orcourse of the truck and simultaneously reduces the excitationamplitudes. By simultaneously reducing the ratio of the amplitude of theexcited oscillation 'to the excitation amplitude, considerably improvedmoving or running properties are obtained in the resonance range.

The invention will be further illustrated by reference to theaccompanying drawings in which FIGURE 1 is a bottom schematic view ofone half of a truck-equipped railway vehicle in which one of the trucksis shown.

FIGURE 2 is a graph in which the ratio of the oscillation amplitude tothe excitation amplitude is plotted over the excitation frequency.

FIGURE 3a shows a first position illustrating the principle of the phaseshift between the spring movement and the damper movement in atransverse direction, the spring suspension system having just attainedthe non-deflected central position while the damper has attained agreater deflection due to rotary movement of the truck,

FIGURE 3b illustrated a further position wherein there is an increase inthe transverse spring deflection and increased deflection of the damper.

FIGURE 30 illustrates a further position wherein the damper deflectionis decreasing while the spring deflection has just attained its maximumvalue,

FIGURE 3d illustrates a further position wherein the deflection of thedamper has been further reduced while the spring deflection still has acertain value,

FIGURE 3e shows a further position wherein the spring deflection is zeroand the damper has a negative deflection.

FIGURE 4 is a fragmentary view in elevation of a portion of a truck anda vehicle body,

FIGURE 5 is a fragmentary top view of a portion of the truck and vehiclebody of FIGURE 4,

FIGURE 6 is a fragmentary view in elevation of a portion of the truck ofFIGURE 4 showing the spring suspension,

FIGURE 7 is a fragmentary view of the truck frame of FIGURE 4 showingthe knife-edge suspension,

FIGURE 8 is an end view of the suspension shown in FIGURE 7,

FIGURE 9 is a sectional view taken on line CC of FIGURE 10,

FIGURE 10 is a top view of a three-axle truck,

FIGURE 11 is a sectional view taken on line AA of FIGURE 9,

FIGURE 12 is a schematic view of a railway vehicle showing dampersmounted toward the ends thereof,

FIGURE 13 is a schematic view of a railway vehicle showing dampersmounted toward the center thereof,

FIGURE 14 is a schematic view of a railway vehicle showing dampersmounted in front of and behind the transverse central plane of thetrucks,

FIGURE 15 is a view in elevation showing a damper connection to a truck,

FIGURE 16 is a sectional view of the connection shown in FIGURE 15,

FIGURE 17 is a schematic view of switch means employed to reversetraveling direction,

FIGURE 18 illustrates a hydraulic damper,

FIGURE 19 illustrates a pneumatic damper,

FIGURE 20 illustrates an electrical damper,

FIGURE 21 illustrates a damper in the form of an eddy-current brake,

FIGURE 22 shows a construction whereby frequencydependent damping iseffected by means of a series connection with an additional spring,

FIGURE 23 shows another construction whereby frequency-dependent dampingis effected by means of a series connection with an additional spring,and

FIGURE 24 shows still another construction whereby frequency-dependentdamping is effected by means of a series connection with an additionalspring.

Referring to FIGURE 1, a bridge carrier member 1 of a railway vehiclehas a truck 2 mounted thereunder, the truck having the wheel sets 3 andbeing mounted on a laterally movable rotary pin 6. The transversesprings 4 serve to absorb lateral impacts. In order to provide for aphase shift between the rotary movement and the translatory transversemovement during the sinusoidal path of the truck 2, a transverseoscillation damper 5 is mounted outside of the vertical transversecentral plane of the truck 2 so that a phase shift will exist betweenthe damping movement and the transverse spring movement.

Referring to FIGURE 2, the vertical line I indicates the position of thenatural frequency of the undamped oscillation whereas the vertical lineII indicates 1.4 times the amount of the natural frequency. The symbol ais the amplitude ratio of the undamped oscillation; b is the amplituderatio of an equal-phase or cophasally damped oscillation with a dampingfactor of 0.3; c is the amplitude ratio of an oscillation with aphase-shifted damping, as obtained in accordance with the constructionof the present invention; and the horizontal line d shows the value ofthe excitation amplitude and, respectively, the value or amount of theoscillation amplitude when the spring action is blocked.

It is apparent from the curve 0, illustrating the phaseshifting damping,that the oscillation amplitudes are considerably reduced by theconstruction of the present invention.

FIGURE 3 illustrates the principle of the phase shift between the springmovement and the damper movement in the transverse direction. Theschematically shown portion of the vehicle body 1 moves in the travelingdirection, indicated by the arrow, and the truck 2 with the wheel sets 3travels on the sinusoidal track 7. The vehicle body executes only minortransverse movements which have been disregarded in the illustration. InFIGURE 3a. the transverse spring action or spring suspension system 4,being positioned in the center of the truck, has just attained thenon-deflected central position thereof whereas the damper 5, beingmounted outside of the transverse central plane, already has attained agreater deflection due to the rotary movement of the truck. FIGURE 3billustrates the increase in the transverse spring path 4 and theincreased deflection of the damper 5. In FIGURE 3c, the damperdeflection already is decreasing again whereas the spring deflection hasjust attained the maximum value thereof. In FIGURE 3d, the deflection ofthe damper 5 has been reduced to zero whereas the spring deflection 4still has a certain value. In FIGUR'E 3e, the zero position of thespring deflection has been reached once more whereas the damper alreadyhas a negative deflection.

In this traveling direction, the damper movement precedes or leads thespring movement, i.e., it is phaseshifted with respect to the springmovement. The transverse oscillations of the vehicle body change onlythe extent of the deflection, but not the phase shift between the springdeflection and the damper deflection. This phase shift results in astronger damping or suppression of the transverse vibrations between thetruck and the vehicle body because the damper paths are greater than inthe case where the damper is positioned within the spring plane andbecause the lead of the damping force, as compared to the spring force,brakes the transverse deflection of the vehicle body more rapidly.

Referring to FIGURES 4, 5, and 6, the transverse damper 5 is mounted atthe end face of a truck, specifically at the end piece or head assembly7a, 0n the bracket 8. The attachment to the bridge carrier is made atthe bracket 9. The truck is provided with coil springs 10 which providethe vertical and transverse spring suspension for the rocker 11. Thevehicle body is supported on the bearing pivot or pin 12.

It is not absolutely necessary that the transverse suspension system ofthe vehicle include coil springs but, instead, the suspension systemalso may be constructed as a pendulum rocker. Of decisive importance isonly the low inherent frequency of the transverse oscillations. FIGURES7 and 8 show a part of the truck frame 2, the pendulums 14, theknife-edge suspensions or bearings 14 of the pendulums 13 as well as thelink suspension or mounting 15 of the suspended spring box 16 upon whichthe rocker springs 10 are supported.

FIGURES 9, 10, and 11 show a three-axle truck 2 and a vehicle bodyportion 1 mounted above it which has a transverse spring suspensionsystem including the coil springs 10. The transverse dampers 5 aremounted outside of the transverse central plane, namely in two planeswith two dampers each. This illustrates an embodiment of the inventionin which the transverse damper is not connected to the end piece or headassembly of the truck, the damping force is produced by two damperswhich operate on the same line of action or effective curve, and thedampers are mounted in front of and behind the vertical transversecentral plane with only those dampers being operative in each case whichare positioned at the front, with regard to the traveling direction.

At the bridge carrier 1, the transverse dampers 5 are mounted on thebrackets 9, and, at the truck frame 2, they are mounted on the brackets8. In this case, the transmission of the tractive force between thetruck and the vehicle body is effected by means of the tie rods 17.

FIGURES 4 through 11 show embodiments of the present invention includingdifferent transverse spring suspension means, i.e., coil springs, andpendulum rockers, and different damper arrangements, i.e., at the headassembly of the truck and at the longitudinal truck carrier, as well asthe production of the damping force by means of different dampercoefficients on the same effective curve (1 damper and 2 dampers).

FIGURE 12 shows an arrangement of the dampers toward the ends of thevehicle. In this arrangement, the transverse vibrations over the leadingtruck are damped or suppressed to an increased extent.

FIGURE 13 shows an arrangement of the dampers toward the center of thevehicle. In this case, the transverse vibrations over the trailing truckare damped or suppressed to an increased extent.

FIGURE 14 shows an arrangement in which the dampers are mounted in frontof and behind the transverse central plane of the trucks. The phaseshifts of the damping forces in front of and behind the transversecentral plane would be mutually nullified without engagement of onedamper and disengagement of the other, and the resulting damping forcewould be as it is in the arrangement for the damping in the springplane. On the other hand, if only the dampers are operative which arepositioned at the front of the trucks, with regard to the travelingdirection, the desired phase shift between the damper deflection and thespring deflection is present.

Where the dampers are of the hydraulic or pneumatic type, those mountedat the front of each truck, with regard to the traveling direction, arerendered operative and those at the rear of each truck, with regard tothe traveling direction, are rendered inoperative by electromechanicalmeans shown in FIGURES 15 and 16. The damper 5 is connected with theframe bracket 8 by means of the links 18 and can move without resistanceas long as the locking pin 19 is attracted by the coil 20. When the coil20 is deenergized, the locking pin 19 is forced into the locking bore 21by the spring 22 so that the damper eye or lug portion 23 is now lockedwith respect to the bracket 8 and the damper is then operative.

Where the dampers are of the electrical type, means also is necessaryfor rendering those dampers operative which are positioned at the frontof each truck, with regard to the traveling direction, and for renderinginoperative those dampers which are mounted at the rear of each truck,with regard to the traveling direction. This is accomplished by means ofthe device for reversing the traveling direction shown in FIGURE 17.When the switch 24 is actuated, it connects the current supply 25 withthe supply lines 26 or 27, depending upon the traveling direction, whichlines connect to the coils of the corresponding dampers.

A transverse vibration damper of the hydraulic type is shown in FIGURE18. A piston 28, which displaces the hydraulic fluid 29, moves in thecylinder 30. The hydraulic fluid is forced through the spring-loadedvalves 31 and 32 which, as a result of flow resistance, produces thedamping force.

A pneumatic damper is shown in FIGURE 19. The piston sleeves 33 and 34displace the enclosed gas 35 during the movement of the piston rod 36.The gas flows through the valves 37 into the opposite chambers and thedamping force is produced by the flow resistance.

An electrical damper is shown in FIGURE 20 The mounting lug 38 isconnected with a coil core 39 which latter is magnetically excited bythe coil 40 and moves in the short-circuited secondary coil 41. Themagnetic field produces a voltage in the coil 41 whereby the dampingforce is generated. The extent or amount of the damping force may beregulated by means of a rheostat instead of short-circuiting the coil41.

FIGURE 21 shows a damper in the form of an eddycurrent brake. Themounting lug 42 is connected with the coil core 43 which carries thecoil 44 through which current flows. The magnetic field produces eddycurrents in the tube 45 during movement of the coil and the dampingforce is produced as a result thereof.

The frequency-dependent damping also can be effected by means of aseries connection with an additional spring. This principle isillustrated in FIGURES 22 to 24. In FIGURE 22, the damper 5 is notmounted directly on the damper eye or lug portion 46 but has a rubberspring 47 positioned in the lug portion 46 and the mounting bolt 48 ispositioned within the rubber spring. The mounting bolt 48 is connectedwith the damper bracket 8. In case of a low damper velocity, i.e., at alow frequency, primarily the damper will move whereas the spring isdeformed only to a limited degree so that nearly the full damping forceof the damper is produced. With increasing damper velocity andfrequency, the spring is deformed more markedly and as a result, thespring assumes an increasing amount of the total movement while theamount assumed by the damper will decrease, whereby the damping effectis reduced.

In FIGURE 23, the damper 5 also is not directly mounted on the mountingbracket through the mounting stud 49, but, instead, is connected withthe fame bracket 8 with the interposition of the helical spring 50.

Similarly, in FIGURE 24, the mounting stud 49 for the damper 5 has therubber spring 51 interposed between the stud and the frame bracket 8.

It will be obvious to those skilled in the art that many modificationsmay be made within the scope of the present invention without departingfrom the spirit thereof, and the invention includes all suchmodifications.

What is claimed is:

1. In combination, a railway truck and a vehicle frame supportedthereby, a transverse spring system between said truck and vehicle framecomprising spring means operatively connected between opposite sides ofsaid truck and said vehicle frame to receive transverse forces, saidspring means having a low natural transverse frequency so that resonanceoccurs at relatively low traveling speeds and the spring system isovercritical at high traveling speeds, and at least one transverseoscillation damper connected between said vehicle frame and a point onsaid truck spaced longitudinally from said spring means and thetransverse central plane of the truck, the damping force of said damperbeing speed dependent, whereby during a sinusoidal path of the truck, aphase shift is present between the damper movement and a transversespring movement, and transverse oscillations are damped at low travelingspeeds with a damping force which is dependent upon the speed of theoscillations.

2. A railway truck construction according to claim 1 in which the damperis mounted adjacent the end of the vehicle.

3. A railway truck construction according to claim 1 in which the damperis mounted adjacent the center of the vehicle.

4. A railway truck construction according to claim 1 including means fordisconnecting the damper.

5. A railway truck construction according to claim 1 in which one damperis mounted adjacent the end of the vehicle, one damper is mountedadjacent the center of the vehicle, and including means fordisconnecting one of the dampers depending upon the direction of travel.

6. A railway truck construction according to claim 1 in which the damperis hydraulic.

7. A railway truck construction according to claim 1 in which the damperis pneumatic.

8. A railway truck construction according to claim 1 in which the damperis electric.

9. A railway truck construction according to claim 7 in which the damperis an eddy-current brake.

10. Apparatus as defined in claim 1 including control means for causingthe damping force of said damper to be greater at low speeds and less athigh speeds.

11. Apparatus as defined in claim 10 wherein said control meanscomprises resilient means connected in series with said damper.

References Cited UNITED STATES PATENTS 1,113,370 10/19-14 Ostendorf267-15 1,179,182 4/1916 Hotmann 267-15 2,040,262 5/1936 Kruckenberg eta1. 105-174 2,071,831 2/ 1937 Hanna 105-82 2,153,389 4/1939 Perkins105-199 2,241,757 5/1941 Baade 105-192 2,349,610 5/ 1944 Brunner 188-892,499,087 2/11950 Bourdon 105-199 2,676,550 4/1954 Burdick 105-1992,705,926 4/ 1955 'Burdick 105-199 2,899,911 8/1959 Lich 105-1992,973,969 3/1961 Thall 188-88 2,988,015 6/1961 Lich 105-199 X 3,020,0062/1962 Warren 188-88 3,240,295 3/1966 Martinek et a1. 188-88 ARTHUR L.LA POINT, Primary Examiner.

HOWARD BELT RAN, Assistant Examiner.

